Compare experts › Stacy Sims vs Kelly & Juliet Starrett

Stacy Sims vs Kelly & Juliet Starrett

Stacy Sims (exercise physiologist) and Kelly & Juliet Starrett (physical therapist; attorney & ceo) side by side: how they train, eat, supplement and sleep, how strong the evidence is, and how to build a plan from either or both.

Build a plan from bothSee the protocols
Words explained (9)
Zone 2
Steady cardio at a pace where you can still talk in full sentences, but not sing.
Intervals
Short hard efforts with easy recovery in between, such as 30 seconds fast, 90 seconds slow.
Loaded carry
Walking while holding something heavy, like shopping bags or dumbbells.
Mobility
Moving your joints freely through their full range.
Creatine
A well-studied supplement that supports strength and muscle.
Omega-3 (EPA, DHA)
Healthy fats found mostly in oily fish such as salmon, herring and sardines.
Time-restricted eating
Eating all your meals within a set window of the day, for example 8am to 6pm.
Perimenopause
The years of changing hormones before periods stop for good.
Hormone therapy (HRT, MHT)
Medicine that replaces hormones that fall at menopause. Only a doctor can prescribe it.

At a glance

MeasureStacy SimsKelly & Juliet Starrett
BackgroundExercise physiologistPhysical therapist; attorney & CEO
Training split60% strength · 10% aerobic · 25% intervals · 5% mobility10% strength · 30% aerobic · 0% intervals · 60% mobility
Signature habitHeavy lifts + sprints10 tests, 10 practices
Protein~2.2 g/kg1.5–2.2 g per kg
Training styleWomen 40+Mobility
Overall evidenceStrongSolid
FollowingInstagram 1.4M · YouTube 372KYouTube 390K

Training splits are our estimates from each expert’s published routine. Following checked October 2026.

The key differences

  • Sims puts more of the week into strength: about 60% against 10%.
  • The Starretts put more of the week into aerobic base (zone 2): about 30% against 10%.
  • Sims puts more of the week into intervals: about 25% against 0%.
  • The Starretts put more of the week into mobility and stability: about 60% against 5%.
  • In plans in their style, Sims' hard sessions are short sprints; the Starretts' are 1-minute intervals.
  • We rate the evidence behind Sims' protocol higher: strong, against solid for the Starretts.
  • Supplements that go into a plan: Sims, creatine monohydrate; the Starretts, none (food first). Prescription items and personal stacks stay out of every plan.
  • Only the Starretts have a mobility or movement routine of their own.

Protocols side by side

Each line is rated for the evidence behind it. “Doctor only” items never go into a plan.

Training

Stacy Sims

  • Strength training 3–4 times a week, 45–60 minutes, built on compound liftsStrong evidence
  • From perimenopause, lift heavy: about 3–5 sets of 6 reps or fewer, leaving 2–3 reps in reserve, with 2+ minutes restSome evidence
  • Sprint intervals of 30 seconds or less, all-out, with full recovery; 1–2 sessions a weekSome evidence
  • Jump and impact work (e.g. squat jumps, box jumps) for bone; one studied protocol is 10–20 jumps twice a daySome evidence
  • Keep easy cardio (walking, easy rides) as recovery; she plays down long moderate-intensity sessions and zone 2 for midlife body-composition goalsPersonal habit
  • 'Ten-minute rule': if you still feel flat after a 10-minute warm-up, scale the session downPersonal habit

Kelly & Juliet Starrett

  • Walk 8,000–10,000 steps a day, up to 12,000 if you canStrong evidence
  • Sit on the floor for at least 30 minutes a day, changing positions (cross-legged, 90/90, long sitting)Personal habit
  • Practise getting down to and up from the floor; test with the sit-and-rise testSome evidence
  • Daily deep-squat time: hold your deepest squat for five breaths as a test, plus sit-stands from a chairSome evidence
  • Daily balance practice; test standing on one leg with eyes closed (SOLEC) and putting on shoes while standingSome evidence
  • Optional rucking: start with about 2 kg for a mile, three times a week, and build up over about a monthPersonal habit

Eating

Stacy Sims

  • Do not train fasted: about 15 g protein before lifting, plus about 30 g carbohydrate before cardio of up to an hourSome evidence
  • After training: 40–60 g protein (perimenopause on) within about 45 minutes, and carbohydrate within 2 hoursSome evidence
  • Daily protein around 2.2 g/kg body weight, the top of the 1.4–2.2 g/kg range in her ISSN position standSome evidence
  • Protein at meals 30–40 g, snacks 15–20 gSome evidence
  • Avoid long fasts, keto and big calorie cuts if active; a small deficit (about 150–200 kcal) in the evening, away from training, if aiming to lose fatPersonal habit

Kelly & Juliet Starrett

  • About 800 g of fruit and vegetables a day (roughly six cups)Strong evidence
  • Protein about 1.5–2.2 g per kg of body weight; some later talks cite 1.8 g per kgSome evidence
  • Choose affordable protein sources that fit your budget; perfection is not requiredNote

Supplements

Stacy Sims

  • Creatine monohydrate 3–5 g a day (start with 1–2 g if unsure), paired with strength trainingStrong evidence
  • Choose third-party tested products (NSF or Informed Sport)Note
  • Vitamin D3, omega-3, collagen and turmeric mentioned as options; no doses givenPersonal habit
  • Iron only if a blood test shows low ferritinDoctor only

Kelly & Juliet Starrett

No specific guidance in what we reviewed.

Sleep & recovery

Stacy Sims

  • Traditional (Finnish-style) sauna at about 60–80 °C after training; she prefers heat to cold for womenSome evidence
  • If using cold water, choose cool (about 16 °C) rather than ice-coldPersonal habit
  • Treat easy days as true recovery between hard sessionsPersonal habit
  • Sees hormone therapy as a valid option for hot flushes and bone risk, but not required for every womanDoctor only

Kelly & Juliet Starrett

  • Aim for at least 7, ideally about 8, hours of actual sleep; track hours asleep for three nightsStrong evidence
  • Keep the same bed and wake times, including weekendsSome evidence
  • Be careful with caffeine and alcohol; keep phones and screens out of the bedroomSome evidence
  • Keep the bedroom cool, dark and quiet, and allow more time in bed than you think you needSome evidence

Stress & mind

Stacy Sims

  • Keep hard intervals short; she says longer efforts and very long sessions raise cortisol, already a concern in menopauseSome evidence
  • In perimenopause, have caffeine with food before training if it makes you shaky or light-headedPersonal habit
  • Listen to your own body and track responses rather than following a fixed planPersonal habit

Kelly & Juliet Starrett

  • Breath-hold test as a rough benchmark for tolerance of carbon dioxidePersonal habit
  • Breathe through the nose during the day and in workoutsPersonal habit
  • Optional mouth-taping at night, building up gradually from about 10 minutesPersonal habit
  • Spend about 180 minutes a week outdoorsSome evidence

Brain health

Stacy Sims

  • Creatine for brain fog and mood; she cites a trial where 5 g a day added to an antidepressant helped women with depressionSome evidence
  • Favours truly hard intervals over moderate or zone 2 cardio for midlife cognitive and metabolic benefitsSome evidence

Kelly & Juliet Starrett

No specific guidance in what we reviewed.

Weak spots to know

Stacy Sims

  • Some researchers say her sex-specific advice goes beyond the evidence. A 2023 umbrella review co-authored by Stuart Phillips found no clear effect of menstrual-cycle phase on strength or training gains, and Sims publicly debated Lauren Colenso-Semple in 2025 on fasted training and protein timing, framed as mechanisms versus outcomes.
  • Her case against fasted training leans heavily on short-term hormone and appetite responses; critics note that longer studies measuring actual fat loss and muscle gain show little difference when daily calories are adequate.
  • Many of her menopause-specific prescriptions (exact sprint lengths, playing down zone 2, tight post-exercise protein windows) come from extrapolation and her own coaching experience rather than trials in midlife women.

Kelly & Juliet Starrett

  • Several central tests rest on observational data: the sit-and-rise and one-leg balance studies show that people who do poorly die sooner, not that practising the test makes you live longer. Both studies were also in Brazilian cohorts and could not rule out other explanations.
  • Some tests have no validated scoring for the general public; the Starretts themselves describe the breath-hold test as a rough benchmark rather than a lab-grade measure, and practices such as mouth-taping have little evidence behind them.
  • Built to Move deliberately leaves out cardio and strength training; for adults over 50 those remain important for heart health and muscle, so the plan works best as a base layer rather than a complete programme. Kelly's earlier Supple Leopard was criticised by one reviewer for a trial-and-error approach rather than a systematic method.

Build a plan from Sims, the Starretts or both

Your free plan shows a week of gym sessions, cardio, a day of eating, supplements and mobility, fitted to your age, time and health.

Plan in Sims' stylePlan in the Starretts' styleMix both

Questions

What is the main difference between Stacy Sims and Kelly & Juliet Starrett?

Their training split differs most in mobility and stability: Sims about 5%, the Starretts about 60% (our estimate from their published routines). Sims' signature habit is Heavy lifts + sprints; the Starretts' is 10 tests, 10 practices.

How much protein do Sims and the Starretts recommend?

Sims: ~2.2 g/kg. The Starretts: 1.5–2.2 g per kg.

Whose advice has stronger evidence?

We rate the evidence behind Sims' protocol higher: strong, against solid for the Starretts.

Do Sims and the Starretts disagree?

Not directly in what we reviewed. Their differences are in emphasis: sims puts more of the week into strength: about 60% against 10%.

Can I combine Sims and the Starretts?

Yes. In Build my mix you choose one expert per area, for example one for strength and another for eating. Your free plan shows the result straight away.

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Full sources are on each profile: Stacy Sims · Kelly & Juliet Starrett. Reviewed October 2026.